Ms Atiqah Mz was rudely awakened by a strong smell akin to burning plastic at about 9.30am yesterday.
Unknown to the 22-year-old, who lives in a 16th-floor flat in Block 45, Lorong 5 Toa Payoh, the unit directly below hers was in flames. Its occupants, a family of five, were not at home at the time.
As there was also smoke in her flat, Ms Atiqah, who is awaiting her tertiary education results, ran out and alerted her next-door neighbours.
In all, about 70 residents were evacuated from the block.
No injuries were reported and the cause of the fire remains unclear, as investigations are still ongoing.
The Singapore Civil Defence Force (SCDF), which was alerted to the fire at 9.40am, said it involved "contents of the living room".
Firefighters put out the flames in about 15 minutes using two water jets, said an SCDF spokesman.
The flat's windows and walls were black with smoke when The Straits Times arrived at the scene at around 10.35am.
Downstairs were a fire engine and several police cars as well as several dozen residents who had run out of their homes during the fire.
The situation was calm, and they were asked to wait at the nearby Toa Payoh East Community Club. By 10.38am, residents from the 14th floor and the lower floors were allowed to return to their flats.
Even at the rubbish chute, there was smoke billowing out.
MRS MARIE MEDRANO, a resident on the 17th floor who is heavily pregnant.
At about 11am, a woman and her three adult sons who live in the affected flat returned but declined to speak to reporters.
A resident on the fourth floor of the block, Ms Dawn Tan, 23, said she smelt smoke when her alarm clock woke her up at 9.30am.
In a panic, the undergraduate also roused her younger brother, Dexter, from his sleep.
"I didn't believe my sister at first... I thought it was the haze," said the 19-year-old student of the Management Development Institute of Singapore.
"A fire engine was already here when they evacuated us," said Ms Tan.
Mrs Marie Medrano, who lives on the 17th floor, left her flat when she saw the smoke.
"Even at the rubbish chute, there was smoke billowing out," the 32-year-old said.
The heavily pregnant housewife then walked down the stairs to join her neighbours.
In 2016, about 70 per cent of fire injuries came from blazes that started in homes, compared with about 40 per cent a decade earlier, Second Minister for Home Affairs Josephine Teo said in Parliament last October.
According to the latest SCDF statistics, 2,818 reported fires - or 68.5 per cent of all fires - took place in residential premises in 2016, 2.8 per cent down from 2015.
These resulted in 26 smoke inhalation cases and 36 burn cases.
The top three types of residential fires were those involving rubbish, unattended cooking and discarded items.
Rubbish fires made up the bulk of all fires at 51.2 per cent.
Correction note: An earlier version of this story said the cause of the fire remains unclear. That is incorrect, as investigations are still ongoing. We are sorry for the error.